Purpose: The association of methadone with Q-T interval prolongation and torsades de pointes (TdP) is reviewed, and recommendations for preventing Q-T interval prolongation in methadone users are ...

A prolonged QT interval increases the risk of polymorphic ventricular tachycardia (Torsades de Pointes) which can result in sudden cardiac death. Long QT 1: The ECG shows broad based T waves.